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CN-121758123-B - Preparation process of high-strength concrete

CN121758123BCN 121758123 BCN121758123 BCN 121758123BCN-121758123-B

Abstract

The invention provides a preparation process of high-strength concrete, which belongs to the technical field of concrete and comprises the following steps of S1, preparing Mg-Al-LDH-NO 2 powder, S2, preparing microcapsules, and S3, mixing and stirring machine-made sand, granite macadam, portland cement, slag powder, limestone powder, metakaolin, microcapsules, water, a water reducer and Mg-Al-LDH-NO 2 powder to obtain the high-strength concrete. The invention can realize the aim of improving the strength and durability of the concrete.

Inventors

  • DENG AIQIN
  • WANG JUNXIA
  • ZHANG YUCHUAN
  • ZHANG XING
  • ZENG JIANBING
  • MENG XIAOPENG

Assignees

  • 洛阳绿筑建筑材料有限公司
  • 河南吉量建材有限公司

Dates

Publication Date
20260508
Application Date
20260305

Claims (8)

  1. 1. The preparation process of the high-strength concrete is characterized by comprising the following steps of: S1, under the light-shielding airtight condition, adding NaNO 2 into a reaction kettle, adding carbon dioxide removal water, adjusting pH, adding Mg-Al-LDH-NO 3 powder, heating, stirring, filtering, quickly washing with the carbon dioxide removal water, and drying to obtain Mg-Al-LDH-NO 2 powder; s2, adding ethyl acetate and poly (methyl methacrylate-co-methacrylic acid) into a reaction kettle under a closed condition, stirring until the mixture is completely dissolved, adding Span 80, transferring into a homogenizer, slowly adding deionized water, transferring into PVA aqueous solution after uniformly mixing, stirring, steaming in a rotating way, and washing to obtain microcapsules; S3, mixing machine-made sand, granite broken stone, portland cement, slag powder, limestone powder, metakaolin, microcapsules and Mg-Al-LDH-NO 2 powder, adding water and a water reducer, and stirring to obtain high-strength concrete; The preparation method of the pre-saturated composite particles comprises the following steps of uniformly mixing silica sol and PVA aqueous solution to obtain composite liquid, placing sodium polyacrylate particles in a stirrer, spraying the composite liquid, drying to obtain composite particles, adding the composite particles into deionized water, and standing in a closed manner to obtain the pre-saturated composite particles; The high-strength concrete comprises, by weight, 720-740 parts of machine-made sand, 1000-1050 parts of granite gravels, 350-370 parts of Portland cement, 100-120 parts of slag powder, 70-90 parts of limestone powder, 50-70 parts of metakaolin, 4-6 parts of microcapsules, 125-154 parts of water, 6.7-8.5 parts of polycarboxylate superplasticizer and 10-12 parts of Mg-Al-LDH-NO 2 powder, wherein the pre-saturated composite particles are 25 parts or 27 parts or 30 parts.
  2. 2. The process for preparing high-strength concrete according to claim 1, wherein in the step S1, the stirring speed is 300-500rpm, and the stirring time is 22-26h, wherein the preparation of the decarbonated water comprises the following steps: And heating deionized water to boiling, naturally cooling to room temperature, and introducing nitrogen to bubble to obtain carbon dioxide-removed water.
  3. 3. The process for preparing high-strength concrete according to claim 1, wherein in the step S1, the preparation of Mg-Al-LDH-NO 3 powder comprises the steps of: Adding carbon dioxide-removed water into a reaction kettle, stirring, adding NaNO 3 to obtain solution A, mixing the carbon dioxide-removed water, magnesium nitrate hexahydrate and aluminum nitrate nonahydrate, stirring to be clear to obtain solution B, heating the solution A, dripping the solution B into the solution A, adjusting the pH value to 9.8-10.2, stirring, transferring into a closed container, and reacting to obtain Mg-Al-LDH-NO 3 powder.
  4. 4. A process for the preparation of high strength concrete according to claim 3, wherein the reaction is carried out at a temperature of 60-80 ℃ for a period of 12-24 hours.
  5. 5. The process for preparing high-strength concrete according to claim 3, wherein the Mg-Al-LDH-NO 3 powder comprises the following components in parts by weight: 6.37-12.74 parts of NaNO 3 , 17.31-34.62 parts of magnesium nitrate hexahydrate and 8.44-16.88 parts of aluminum nitrate nonahydrate.
  6. 6. The process for preparing high-strength concrete according to claim 1, wherein the microcapsule comprises the following components in parts by weight: 90-99 parts of ethyl acetate, 10-11 parts of poly (methyl methacrylate-co-methacrylic acid), 80-1.1 parts of Span, 20-22 parts of deionized water and 400-440 parts of PVA aqueous solution.
  7. 7. The process for preparing high-strength concrete according to claim 1, wherein the solid content of the silica sol is 20-30wt%, the concentration of the PVA aqueous solution is 0.8-1wt%, the particle size of the sodium polyacrylate particles is 0.3-0.6mm, and the spraying time is 5-8min.
  8. 8. The process for preparing high-strength concrete according to claim 1, wherein the pre-saturated composite particles comprise the following components in parts by weight: 80-90 parts of silica sol, 10-12 parts of PVA aqueous solution, 95-105 parts of sodium polyacrylate particles and 2500-3000 parts of deionized water.

Description

Preparation process of high-strength concrete Technical Field The invention relates to the technical field of concrete, in particular to a preparation process of high-strength concrete. Background With the development of high-rise buildings, large-span bridges, heavy load structures and special protection projects, the traditional common concrete has difficulty in meeting the increasingly growing design requirements in terms of mechanical properties and durability. At present, the concrete strength is improved mainly by technical means of optimizing a cementing material system, adopting a high-efficiency water reducing agent, doping active mineral admixture (such as silica fume, slag powder, fly ash and the like) and optimizing aggregate grading and the like in the industry. However, although the existing high-strength concrete technology is advanced on a single strength index, the technology still has outstanding defects in the aspect of comprehensive performance balance, for example, the shrinkage cracking risk is aggravated by the high glue consumption, and the long-term durability and the safety of a concrete structure are affected. In addition, in actual engineering, the formation of concrete is often randomly interfered by a plurality of factors, so that the problems of insufficient actual strength and unbalanced performance of the concrete and poor durability and stability of the concrete are easily caused. The patent application document with the publication number of CN107986648A discloses slag silicate cement and a preparation method thereof, wherein the slag silicate cement comprises, by weight, 50-60 parts of silicate cement clinker, 3-5 parts of gypsum, 25-35 parts of granulated blast furnace slag, 3-5 parts of limestone, 5-10 parts of kiln dust, 2-5 parts of zeolite, 0.1-0.3 part of grinding aid, and the grinding aid comprises, by weight, 5-15 parts of triethanolamine acetate, 3-8 parts of glycerol, 1-5 parts of ethylene glycol, 0.5-2 parts of a water reducer, 3-8 parts of sodium thiosulfate and 50-60 parts of water. According to the scheme, grinding efficiency is improved, early strength is enhanced by introducing a grinding aid into a cement grinding and batching system, grinding is promoted by a chlorinated hydrocarbon-containing system and chloride ions are generated, the system is easy to conflict with the durability of concrete, and meanwhile, a lignosulfonate water reducing system is weaker in water reducing and slump retaining capacity than high-strength concrete in low-water-cement ratio, and the key durability problems such as self-shrinkage cracking and long-term impermeability are not solved. Accordingly, there is a need to provide a process for preparing high strength concrete to solve the above problems of the prior art. Disclosure of Invention In view of the above, the present invention provides a process for preparing high-strength concrete, which can achieve the purpose of improving the strength and durability of the concrete. In order to achieve the above object, the present invention provides a process for preparing high-strength concrete, comprising the steps of: S1, under the light-shielding airtight condition, adding NaNO 2 into a reaction kettle, adding carbon dioxide removal water, adjusting pH, adding Mg-Al-LDH-NO 3 powder, heating, stirring, filtering, quickly washing with the carbon dioxide removal water, and drying to obtain Mg-Al-LDH-NO 2 powder; s2, adding ethyl acetate and poly (methyl methacrylate-co-methacrylic acid) into a reaction kettle under a closed condition, stirring until the mixture is completely dissolved, adding Span 80, transferring into a homogenizer, slowly adding deionized water, transferring into PVA aqueous solution after uniformly mixing, stirring, steaming in a rotating way, and washing to obtain microcapsules; And S3, mixing machine-made sand, granite broken stone, portland cement, slag powder, limestone powder, metakaolin, microcapsules and Mg-Al-LDH-NO 2 powder, adding water and a water reducer, and stirring to obtain the high-strength concrete. The intercalation conversion from Mg-Al-LDH-NO 3 (LDH refers to layered double hydroxide) to Mg-Al-LDH-NO 2 (LDH refers to layered double hydroxide) is realized under the conditions of light-shielding and airtight and alkalinity, the light-shielding and airtight conditions can inhibit the slow oxidation trend of nitrite under the condition of light/oxygen, the stable anion morphology is maintained, the stable existence of nitrite in NO 2- can be ensured in the alkaline environment, and HNO 2 is avoided. When external Cl - enters the concrete, the external Cl - can be subjected to anion exchange with NO 2- in Mg-Al-LDH-NO 2, so that Cl - is fixed, and the capture of Cl - is realized, so that the effective concentration of free Cl - in the concrete can be reduced, the driving force of migration of Cl - to a reinforcing steel bar/interface area is weakened, and the chlorine salt corrosion resistance o